The Andromeda Galaxy appears as a small diagonal streak on the left side of the map, below the Milky Way's galactic plane, and bright smudges below center on the right side mark two other galactic neighbors, the Large and Small Magellanic clouds. (Click here for a labeled map.)

Toward the top and bottom of the map, away from the foreground structures of the Milky Way and its companion galaxies, is the cosmic microwave background (CMB) radiation, remnant light emitted 380,000 years after the big bang. An earlier NASA satellite, the Wilkinson Microwave Anisotropy Probe (WMAP), uncovered a bounty of cosmological data by measuring subtle temperature fluctuations across the CMB, and Planck promises to take an even closer look, potentially providing a test of key cosmological theories.

Now that Planck has mapped the sky, the hard work begins; researchers must painstakingly remove the foreground light sources to get a clear view of the cosmic microwave background. According to a news release from NASA, a participant in the mission, the process will take about two years.